Reposting this:

# strace -p 443

Process 443 attached - interrupt to quit futex(0x4030e144, FUTEX_WAIT_PRIVATE, 2, NULL

locks up. Stops, stalls ... fails to continue ....

Now tried several alsa-lib versions. A clue would be nice? What do I replace to fix this ?

Anyone ?

Thanks, Jon

On Thu, 2012-02-16 at 12:01 +0000, Jonathan Andrews wrote:

Sorry all me again.

I've written a program that picks up UDP broadcast packets containing audio from a number of sources, mixes it together and presents it to alsa for playback.

I'm experiencing random freezes. I cant reproduce then running the process under strace as the process on the ARM board slows down to the point it underruns with ALSA all the time and the symptom doesn't show.

If I attach strace after the process has frozen I get this and nothing else:

# strace -p 443 Process 443 attached - interrupt to quit futex(0x4030e144, FUTEX_WAIT_PRIVATE, 2, NULL

This stop happens at random at any point typically after minutes but run time can be over an hour.

I need to work around this as I need the board for a demo.

Im using, alsa-lib-1.0.25 kernel 2.6.36.4 BusyBox v1.19.2

I also compiled strace for arm, but this and a busybox shell is the only environment I have on the board.

The problem showed when I starting using this function to poll alsa:

The same code on my PC dual core AMD does not seem to suffer the problem : alsa-lib-1.0.23, Linux jonspc 2.6.32.26-175.fc12.i686 #1 SMP

Before anyone points it out I want to poll as alsa is not the only sound output supported by the code.

int sound_system_needs_data_now() { int framesleft; snd_pcm_status_t *status; snd_pcm_status_alloca( &status );

    // If the alsa playback has stalled then it definately needs data
    snd_pcm_status(playback_handle,status);
    if( snd_pcm_status_get_state( status ) != SND_PCM_STATE_RUNNING )
            return(TRUE);

    framesleft=snd_pcm_avail (playback_handle);

//printf("FL=%d\n",framesleft); fflush(stdout);

    if (framesleft>1000)
            return(TRUE);
    else
            return(FALSE);

}

Stuck process

# cat /proc/443/status Name: udp-many-way-au State: S (sleeping) Tgid: 443 Pid: 443 PPid: 392 TracerPid: 0 Uid: 0 0 0 0 Gid: 0 0 0 0 FDSize: 32 Groups: VmPeak: 4356 kB VmSize: 4292 kB VmLck: 132 kB VmHWM: 1788 kB VmRSS: 1788 kB VmData: 396 kB VmStk: 136 kB VmExe: 28 kB VmLib: 3348 kB VmPTE: 12 kB VmSwap: 0 kB Threads: 1 SigQ: 0/471 SigPnd: 0000000000000000 ShdPnd: 0000000000000000 SigBlk: 0000000000002000 SigIgn: 0000000000000006 SigCgt: 0000000180002000 CapInh: 0000000000000000 CapPrm: ffffffffffffffff CapEff: ffffffffffffffff CapBnd: ffffffffffffffff Cpus_allowed: 1 Cpus_allowed_list: 0 Mems_allowed: 1 Mems_allowed_list: 0 voluntary_ctxt_switches: 5908 nonvoluntary_ctxt_switches: 1766

Any useful suggestions welcome.

Thanks, Jon

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